Bio-oil production from oil palm biomass via subcritical and supercritical hydrothermal liquefaction

- Water is used as a green solvent to liquefy palm biomass to bio-oil.
- The optimum liquefaction condition of oil palm biomass is 390 °C and 25 MPa.
- The optimum condition corresponds to the lowest density of water.
- The optimum condition corresponds to the lowest dielectric constant of water.
- The maximum bio-oil yield in this study is 38.53 wt%.